1. Field of Invention
The present invention relates to an anti-leakage apparatus for toilet tanks.
2. Related Prior Art
Toilet tanks are automatically refilled with water after water is released therefrom. Each toilet tank has an input valve and an output valve. The level of water contained in the toilet is initially retained at a highest point. At this instant, the input and output valves are both shut. Once the output valve is opened for releasing water out of the toilet tank for flushing, the input valve is automatically opened for refilling the toilet tank with water. Although water is filled into and released out of the toilet tank synchronously, water decreases in the toilet tank as the rate of flow passing through the input valve is much slower than the rate of flow passing through the output valve. That is, the level of water contained in the toilet tank gets lower. The output valve is shut again when the level of water contained in the toilet tank reaches a lowest position. At this instant, the input valve is still open for refilling the toilet tank with water so that the level of water contained in the toilet tank gets higher. The input valve is shut when the level of water contained in the toilet reaches the highest point again. Normally, those functions should take place automatically, except for opening the output valve. That is, the toilet tank is no longer manually monitored after the output valve is opened. However, the input valve will always be opened for inducing water into the toilet tank when the output valve cannot be properly shut again. Such a leakage might cause a serious waste of water. Therefore, the present invention is intended to solve the above-mentioned problem by providing an anti-leakage apparatus.